Jeff Wise over at Psychology Today explains how psychopaths and sociopaths can often detect the behavior of easier victims just by the way they walk:

[P]sychologists have long known that the more psychopathic a person is, the more easily they can identify potential victims. Indeed, they can do so just by watching the way a person moves. In one study, test subjects watched videos of twelve individuals walking, shot from behind, and rated how easily they could be mugged. As it happened, some of the people in the videotapes really had been mugged — and the most psychopathic of the subjects were able to tell which was which.

The stride, shifting of weight, and the way potential victims lifted their feet demonstrated their level of confidence very obviously to the more psychopathic subjects of the study. Socially submissive body language was key in choosing the right victims. Signs include "a lack of eye contact, fidgeting of the hands and feet, and the avoidance of large gestures when shifting posture."

While nobody's blaming victims here, it's still worth knowing how your body language may make you a more attractive candidate to potential predators. While not every criminal is going to go after the easiest targets, you might improve your chances of avoiding victimization by looking confident when you walk down the street at night.